Place apples in a greased 9x13 baking dish. In a heavy saucepan or microwave, 2/3 of the bag of caramel bits with 2 tablespoons half and half, stirring often; drizzle over apples. In a bowl, combine the flour, oats, brown sugar, walnuts, salt and cinnamon; cut in butter until mixture resembles coarse crumbs. Sprinkle over apples.
Bake at 375 degrees for 45 to 50 minutes or until golden brown. Cool for 10 minutes. Meanwhile, in a heavy saucepan or microwave, melt remaining caramel bits with remaining half and half, stirring often until smooth. Drizzle over dessert and ice cream when serving.